Breast cancer is the second leading cause of cancer related death in women. Because chemotherapy for metastatic disease is not curative, the search for better drugs, improved methods of treatment delivery, and patient protection against drug induced toxicity is ongoing. This is a phase I and II study of Doxil and Navelbine in patients with metastatic breast cancer. Significant single agent activity has been demonstrated with both doxorubicin and vinorelbine (Navelbine) in patients with metastatic breast cancer and the combination of these two agents may be even more active. Unfortunately significant myelosuppression has occurred with this regimen. Doxil appears to be a promising new formulation of doxorubicin. Its safety and pharmacokinetic profile has been demonstrated in human studies. Preliminary evidence indicates significant activity in solid tumors including breast cancer. We believe the combination of Doxil and Navelbine merits investigation for the following reasons: (1) This regimen is likely to be highly active in patients with metastatic breast cancer; (2) Alopecia should be uncommon; (3) Nausea and vomiting should be minimal; (4) myelosuppression should be less severe than with doxorubicin and navelbine; (5) Doxil may not be cardiotoxic. This phase I dose escalation study will evaluate the toxicity of the regimen and to define the maximally tolerated dose. Following determination of the MTD, a phase II study will assess the efficacy of the regimen. The specific objectives of the study are: (1) assess toxicity and define MTD (phase I); (2) Determine overall objective response rate using the MTD defined in phase I; (3) Determine time to progression and duration of response; (4) Evaluate the pharmacokinetics of the combination of Doxil and Navelbine; (5) In women with tumors which are assessable by biopsy, to determine the tumor concentration of Doxil.